1. Field of the Invention
This invention is a new and unified three dimensional monitoring system that is useful in intercepting and monitoring leachates and other fluids that escape from any of the types of structures and areas for collecting, storing and/or treating of hazardous waste material. The schedule for recording the activity at each vertical pipe station gives an early warning of any potential problem and an estimate of the leachate production from the sources, such as a landfill.
2. Description of the Related or Prior Art
There is limited background art for monitoring hazardous waste where some past practices included dumping into the nearest stream or any convenient place without thought of the consequence. Some family units and/or municipalities channeled liquid waste to cesspools or lagoons and hauled the more solid waste to dump areas or a dugout or valley with little or no consideration for ground water or any form of monitoring. Some of these practices continue in less densely populated areas today. Some large world cities have continued their refuse piles since medieval times.
The advances in computer science have produced the "Geographic Information System," commonly referred to as GIS. Geographic reference data are conveniently handled. Digitized data sources are available through the U.S. Geological Survey, State Geological Surveys, State Water Commissions, the U.S. Soil Conservation Service, and others.
The Environmental Protection Agency (EPA) has clear practical regulations for assessing landfill performance with their Hydrologic Evaluation of Landfill Performance, known as the HELP model. This model is readily available and uses all of the hydraulic, soil and barrier soil parameters including liners, and their leakage fractions, slope, area, natural internal and lateral drainage precipitations, and geologic setting and water table.
With the data and guides from EPA, the State Health Departments can assess their regional and local ground water pollution potential and designate, with the aid of the Water Commission and Federal and State Geological Survey, hydrologically sensitive areas to help in the selection of waste sites and comply with the legal standards that are emerging with experience. Simple compaction of the waste, leaking liners, and cover soil to protect from rodents and flies is no longer tolerated or legal. Methods of monitoring are introduced with each design that is patented for compartments for receiving and storing hazardous waste, including pits, bins, and vaults above ground that employ down spouts rather than mechanical pumping from a liquid collection arrangement for accumulating leakage or leachate from the bin or secondary temporary storage facilities. Other devices with a hopper-like holding compartment lined with liquid impervious liners and a leakage treatment compartment below the hopper bottom, and a drain system for further treatment and/or disposal is reported by U.S. Pat. No. 4,624,604, Nov. 25, 1986. Even these landfills and surface impoundments may leak chemical waste which could enter the natural ground water supply, especially where ten years is considered the life of some liner material.
This prior art used by some municipalities, land managers and other hazardous waste generators includes randomly drilled wells in, and/or near the edges of the deposits. This is followed at places by visual and photographic monitoring by airplane to chart the results of surface reclamation of the waste site. This sees only the surface.
Today, monitoring begins with modeling for the pollution potential known by the acronym DRASTIC. This uses a simple summation of weighting times a factor to obtain an index, using Depth to water, net Recharge, Aquifer, Soil media, Topography, Impact of vadose zone media, and hydraulic Conductivity. The site selected and approved is then constructed according to specifications for the type of waste material. The pits, bins and impoundments or landfills may have a considerable range in depth from 20 feet and more to surface facilities and areas of less than 2 acres to more than 20 acres. This data base is the true beginning of monitoring and requires a unified monitoring system to control all parts of the disposal site not given (included) in the prior art.